1. Technical Field
The disclosure relates generally to a fibrin glue applicator system for dispensing a first and a second component of a tissue sealant based on human or animal proteins and, more particularly, to an applicator system for dispensing a first and a second protein solution to be applied to tissues or organs to form a fibrin sealant for sealing wounds, stopping bleeding and the like.
2. Description of Related Art
A fibrin sealant is a biological adhesive formed by mixing two protein components, namely, fibrinogen and thrombin. Each protein component is derived from human plasma and is subjected to virus elimination procedures. The components are typically individually dehydrated and stored in separate vials as sterile freeze-dried powders.
It is known that purified fibrinogen and thrombin, together with a variety of known adjuvants, can be combined in vitro to produce a polymer having great potential benefit, both as a hemostatic agent and as a tissue adhesive. Because of the rapid polymerization upon intimate interaction of fibrinogen and thrombin, it is important to maintain these two blood proteins separate until applied at the application site. These protein solutions are generally mixed and dispensed by devices such as a dual syringe apparatus.
One dual syringe apparatus for applying a fibrinogen-based tissue adhesive is disclosed in U.S. Pat. No. 4,359,049 to Redl et al. This reference discloses a mechanism in which two standardized one-way syringes are held in a support having a common actuating means. The dispensing end of each syringe is inserted into a collection manifold where the two components are mixed. The components are then dispensed through a common needle capable of covering a limited area of the application site.
Typical devices for mixing and dispensing solutions of fibrinogen and thrombin require the addition of these proteins in powdered form to the body of the syringe. This makes the proteins susceptible to contamination by impurities which may enter the syringe body. Further still, the use of the syringe body to mix the proteins with water to create the protein solutions can cause the solutions to leak out from either the dispensing end of each syringe or the proximal end of the syringe body.
A dual syringe apparatus for the application of fibrinogen and thrombin solutions to an application site generally contains several parts, such as a syringe plunger, a xe2x80x9cYxe2x80x9d manifold connector, a dispensing needle, a syringe holder, syringe needles, and conduits for transporting the solutions to the dispensing needle. Therefore, fibrin sealant applicators, such as disclosed in U.S. Pat. No. 4,359,049 to Redl et al. discussed above, and in U.S. Pat. No. 4,874,368 to Miller et al. and U.S. Pat. No. 4,979,942 to Wolf et al. are difficult to reuse. The replenishment of the protein components typically requires removing a clip which couples the syringe plunger, removing the syringe plunger, detaching the syringes from the xe2x80x9cYxe2x80x9d connector, removing the syringes from the holder, inserting new syringes, affixing the syringes to the xe2x80x9cYxe2x80x9d connector, adding fibrinogen to one syringe and thrombin to another syringe, adding sterile water to each syringe, replacing the syringe plunger, replacing the plunger clip, and mixing the solutions. In an application where time may be of the essence, such a lengthy replenishing process is impractical and cumbersome.
A fibrin glue applicator system is provided for dispensing a first and a second protein solution. The first and second protein solutions form a biological adhesive when intermixed on an application site. The fibrin glue applicator system includes a coupler interface, a disposable loading unit (DLU), and a housing having a handle portion which includes a trigger operatively associated with a slide bar for dispensing the solutions from the DLU. The coupler interface is removably mounted to the DLU and the DLU is removably mounted to the housing.
The DLU includes two piston assemblies for storing the solutions therein before the solutions are dispensed. Each piston assembly includes a cylinder which matingly engages a piston having a rod which translates proximally and distally within the cylinder. The piston assemblies are connected to one another by a loading lever at a proximal end and a dispensing unit at a distal end for holding the assemblies substantially parallel to one another.
The coupler interface includes two mounting holes each having a piercer therein for receiving a vial having the first protein solution and a vial having the second protein solution. The protective seal on each vial is pierced by the piercer within each hole when the vials are inserted therein. Each piercer is in fluid communication with one of the cylinders of the DLU via a conduit connected to a main conduit. A first one-way valve is included within each conduit to open and close a path leading from the piercer to the main conduit. The first one-way valves are forced open by air pressure created when the loading lever connected to the two pistons of the DLU is translated proximally causing the protein solutions to be transferred to their corresponding cylinder.
When the protein solutions have been transferred from the vials to the cylinders of the DLU, the vials and the coupler interface can be removed from the DLU. The DLU is then mounted to the housing for dispensing the protein solutions from the cylinders to the application site.
The solutions are dispensed via two dispensing orifices each in fluid communication with one of the main conduits. A second one-way valve is fixed within each main conduit in proximity to each dispensing orifice to open and close a path leading from each cylinder to its corresponding dispensing orifice. The second one-way valves open when the solutions are forcibly transferred from the cylinders to the main conduits. The solutions are forcibly transferred when the pistons are translated distally by pressing the trigger of the handle portion to translate the slide bar distally which causes the loading lever to translate distally which in turn causes the pistons to translate distally thus creating pressure within the cylinders for dispensing the solutions within the main conduits. The first and second protein solutions are preferably fibrinogen and thrombin solutions which intermix on the application site to form a fibrin sealant.